1. Field of the Invention
The invention relates to a homokinetic displacement joint for longitudinal shafts of motor vehicles, consisting of an outer and inner joint body as well as a cage. Several balls are provided between the joint bodies and each ball is guided in tracks/grooves on the joint bodies, and held in a cage window of the cage. A torque can be transferred from the outer joint body onto the inner joint body, or from the inner joint body onto the outer joint body, using the balls.
2. The Prior Art
Displacement joints that are used in motor vehicles to transfer torques are well known. They consist of an outer and an inner joint body that are structured with tracks/grooves, and balls are provided in these grooves. The displacement joints are configured with cages or without cages. The transfer of the torque from one joint body to the other takes place by way of the balls inserted into the grooves.
Thus, German Patent No. DE 197 04 761 C2 describes a ball homokinetic joint in the form of a displacement joint in which two ball tracks adjacent to one another on the circumference of the outer joint part each have center lines that are parallel to one another, and form outer track pairs, and two ball tracks that are adjacent to one another on the circumference of the inner joint part each have center lines that are parallel to one another, and form inner track pairs. The outer and inner tracks pairs are assigned to one another and together accommodate a pair of balls. Two of the ball tracks in the inner joint part and the outer joint part are brought close to one another, so that the cage windows can be relatively lengthened there, where two tracks that run at opposite intersection angles to the longitudinal axis are adjacent to one another in a joint component, in the circumference direction. It is explained that it is an advantage that the existing residual ridge width between the extended cage windows does not become impermissibly narrow.
An axially displaceable homokinetic rotary joint having an outer joint body and an inner joint part as well as balls provided between these two components is described in European Patent No. EP 1 039 162 A2, in which each ball is guided in a track on the joint body, and held in a cage window of a cage. To reduce the occurrence of noise, a damping layer is provided on the inside surface of the joint body that can be brought into contact with the outside surface of the cage, and/or on the essentially radial insides of the cage windows. This eliminates the so-called “humming-buzzing” of homokinetic joints.
Also, displacement valves that do not have cages are known, as described in German Patent No. DE 199 58 147 A1, for example. This displacement joint relates to a homokinetic displacement joint consisting of an outer joint piece having exterior joint piece tracks, and an inner hub with exterior hub tracks that intersect the joint piece tracks. Joint piece tracks and hub tracks that correspond to one another each form a raceway track for a ball that transfers force. All of the raceways have a slant angle, relative to the first plane which is configured essentially the same size, for the related joint piece track and for each corresponding hub track, but in the opposite direction. Some of the raceways additionally have an incline angle with regard to a second plane, which is also configured essentially the same size for the related joint piece tracks and for each corresponding hub track, but in the opposite direction. This is supposed to bring about the result that all of the balls of the displacement joint are involved in the transfer of power.
It is a disadvantage of the known displacement joints that much production technology effort is required for their production, and that the ratio of the construction size of these displacement joints to their transfer capacity is very disadvantageous.